In the car industry, savings in fuel consumption are achieved by reducing the weight of the car. Car bodies are consequently increasingly made from light-weight materials, such as aluminum or fiber-reinforced resin. These materials create new challenges for attaching electric connectors to the car body, such as a ground stud, as the ground stud may come loose more easily than with conventional car bodies. Moreover, as modern cars comprise more and more technology, filling up the available installation spaces in the car, the contact studs of the car body are often difficult to access and difficult to see for forming connections.